This invention is an assembly and for mounting an oversized rear wheel along the centerline of a motorcycle.
Typically, motorcycles are equipped with standard sized front and rear wheels of the same width. Motorcycle owners enjoy spending time on the care and maintenance of their motorcycle and often seek to make their motorcycle unique by adding custom features. A popular custom feature is the installation of an oversized rear wheel. An oversized rear wheel highlights the appearance of power sought by many owners of larger motorcycles. Installation of an oversized tire adds to the aesthetic appearance of the motorcycle, and provides practical benefits. One practical benefit is the improvement in ride obtained by the increased width of the oversized tire. Further, an oversized tire improves the handling, maneuverability, and traction of the motorcycle.
Installation of an oversized tire presents certain design challenges, the main challenge being installation of the oversized wheel within the original frame members. A further challenge is presented in routing power from the transmission to the oversized rear tire. As appreciated, a rear tire with an increased width will no longer align with the drive pulley or sprocket from the drive transmission. Prior art assemblies have attempted to account for this misalignment by moving the rear tire to one side and the engine and transmission to the opposite side to provide additional room required to account for the increased width of the oversized tire. Such modifications purposely mis-align the front and rear wheels in an effort to accommodate the oversized rear tire, thereby creating a less stable ride. Further, movement of the engine and transmission changes the center of gravity of the motorcycle from that of the factory design to further increase the instability of the motorcycle.
Another means of accounting for the larger tire is to provide a sprocket or drive pulley spaced outwardly from the transmission to align with the oversized rear tire. Such a solution can practically accommodate only slightly oversized tires. Further, increasing the distance of the drive pulley from the transmission creates a safety hazard in that the drive belt or chain is positioned at a point closer to a rider""s leg.
For these reasons it is desirable to produce an assembly that provides for proper alignment of the front and rear tires, can accommodate any width oversize tire and does not create safety hazards for riders.
The assembly of this invention is a rear tire assembly for mounting an oversized tire including an intermediate pulley assembly driven by a drive of the transmission including first and second intermediate pulleys rotating in concert about a common shaft. The second pulley is spaced apart from the first intermediate pulley to accommodate extra width of the oversized tire.
The swing arm of this assembly includes extension arms spaced apart to accommodate the oversized tire along with the driven pulley. The swing arm includes a drive plate for mounting the intermediate pulley assembly and an idler pulley. The single drive belt is replaced by short and long drive belts or chain links. The short drive belt transmits torque from the transmission of the motorcycle to the first intermediate pulley. The first and second intermediate pulleys are connected such that rotation of the first intermediate pulley rotates the second intermediate pulley. The second intermediate pulley is spaced apart from the first intermediate pulley to align the long drive belt with the driven pulley on the oversized pulley. The intermediate pulley assembly pivots with the swing arm and the idler pulley maintains tension on the short drive belt during such pivoting.
Accordingly, the assembly of this invention provides proper alignment between front and rear tires, and can accommodate any width oversize tire while providing improved ride and performance.